BALTIMORE, Nov. 29 (UPI) -- A number of studies in the United States and Denmark appear to have debunked the widely held belief there is a connection between cancer and stress.
But the research has led to an even more interesting finding, the New York Times reports. Researchers discovered many cancer cells release proteins that trick the immune system into ignoring them, while tumors excrete substances that recruit the immune system into helping them metastasize.
"We knew very little about what regulated these immune responses to tumors until very recently," Dr. Drew Pardoll of Johns Hopkins University said. "We now are in a position to totally rewrite the book."
A few cancers occur generally in patients with weakened immune systems, Pardoll and other researchers say. They tend to be comparatively rare cancers related to infections, like Kaposi's sarcoma and stomach cancer.
The assumption had been that stress weakens the immune system, making cancer more likely. Now doctors say that it is the cancer itself that weakens the immune system.
